High temperature processing of photographic silver halide elements

ABSTRACT

A method for producing photographic images by development of an exposed silver halide element at elevated temperature is provided wherein the development occurs in the presence of a nitrile compound selected from the group consisting of: (a) benzene compounds carrying at least 2 cyano groups, (b) pi -deficient heterocycles carrying at least 1 cyano group on the heterocyclic nucleus, and (c) compounds carrying at least one cyano group on an olefinic group, which correspond to the formula:   The nitrile compounds have a favourable effect on the sensitometric properties of the silver halide emulsion that are developed at elevated temperature. They reduce the supplemental fog produced by development at elevated temperature.

United States Patent [191 Pollet et al.

HIGH TEMPERATURE PROCESSING PHOTOGRAPHIC SILVER HALIDE ELEMENTSInventors: Robert Joseph Pollet, Vremde',

Antoon Leon Vandenberghe, Hove;

Hubert Vandenabeele, Mortsel,all of Belgium Agfa-Gevaert N.V., Mortsel,Belgium Filed: Sept. 14, 1972 Appl. No.: 289,093

Assignee:

Foreign Application Priority Data Sept 17, 1971 Great Britain 43518/71US. Cl 96/66.3, 96/66.5, 96/95, 96/109, 96/48 QP Int. Cl. G03c 5/30,G036 l/O6, G036 l/34 Field of Search 96/48 QP, 63, 66, 66.3, 96/66.5,109, 95

References Cited UNITED STATES PATENTS 12/1968 Stevens et al. 96/109 R8/1969 Duffin et al 96/109 R 2/1971 Oguchi et al 96/109 R 4/1973 Riesteret al 96/95 11/1973 Okutsu et al. 96/66.5

[ 1 Oct. 15, 1974 Primary Examiner-Mary F. Kelley Attorney, Agent, orFirm-A. W. Breiner [57] ABSTRACT wherein: R is a cyano group or arr-deficient heterocycle, and R is an aryl group, a substituted arylgroup, a heterocycle or a substituted heterocycle. The nitrile compoundshave a favourable effect on the sensitometric properties of the silverhalide emulsion that are developed at elevated temperature. They reducethe supplemental fog produced by development at elevated temperature.

9 Claims, No Drawings The present invention relates tothe development atincreased temperature of exposed photographic radiation sensitive silverhalide elements.

In normal processing of exposed photographic mate'- rials development iscarried out at ambient temperature (about 20 C) and requires arelatively long time say several minutes. Therefore, there isa generaltrend to enhance the speed of processing, which can be done by carryingout development and the other processing operations at elevatedtemperatures. Rapid development of photographic elements occurs attemperatures above 30 C and preferably between 35 and 45 C.

When the processing of exposed photographic silver halide elements iscarried out at elevated temperatures i.e., above 30 C these elementshave a tendency of showing increased fog and generally the othersensitometric characteristics are impaired also.

It is known to reduce the formation and growth of fog in photographicsilver-halide elements by means of antifoggants or stabilizers e.g.heterocyclic mercapto compounds such as l-phenyl-5-mercapto-tetrazoleand azaindenes, more particularly tetraor pentaazaindenes, especiallythose substituted by hydroxy or amino groups eg 5-methyl-7-hydroxy-s-triazolo-[ 1,5- a]pyrimidine. The latter compoundsare used to stabilize the emulsion against formation and growth of fogwhen the photographic materials are stored before use. The compoundshave only a relatively weak effect in reducing fog formation when thephotographic materials are used immediately after preparation.l-Phenyl-5- mercaptotetrazole, on the contrary, has a high fogreducingeffect immediately after the preparation of the photographic emulsions.Therefore, both compounds are generally used together in the emulsion.

However, the supplemental fog producedby the processing at elevatedtemperatures cannot be reduced sufficiently by means of the conventionalantifoggants or stabilizers.

It has now been found that nitrile compounds selected from the groupconsisting of (a) benzene compounds carrying at least two cyano groupsonthe benzene nucleus (b) vr-deficient heterocycles e.g. pyridine,quinoline, isoquinoline, etc. carrying at least one cyano group on theheterocyclic nucleus and (c) compounds carrying at least one cyano groupon an olefinic group and corresponding to the formula:

G=CHR2 wherein:

1 stands for a cyano group or a vr-deficient heterocycle, and

the emulsion speed to a noteworthy extent or even in some cases with anincrease of the emulsion speed. Other compounds give rise to an increaseof the speed and/or gradation without showing a noteworthy influence onthe fog.

As is known by those skilled in the art of organic chemistry and, as canbe learned from A. Albert Heterocyclic Chemistry pages 34 and 39,University of London, The Athlone Press, 1959, ir-dcficient heterocyclesare completely unsaturated heterocyclcs having nitrogen as the solehetero-element and a deficit of 'rr-electrons elsewhere, moreparticularly heterocyclcs derived from carbocyclic aromatic ring systemswherein one or more =Cl-lgroups are replaced by =N groups.

Thus, the present invention provides a method of producing photographicimages, which comprises developing an exposed photographic elementcomprising a support and at least one photographic silver halideemulsion, at a temperature above 30 C wherein the said development iscarried out in the presence of at least one nitrile compound as definedabove.

The nitrile compounds of use according to the invention are particularlyuseful in photographic silver halide materials, which are stabilizedagainst formation and growthof fog by means of azaindene compounds asdescribed above and therefore the present invention also provideslight-sensitive silver halide materials, which comprise an azaindenestabilizer, especially 5 methyl- 7hydroxy-s-triazolo-[l,5-a]pyrimidine,and a nitrile compound as defined above.

The following are representative examples of nitrile compounds whichwere found particularly suitable for use accordingto the presentinvention. Where deemed necessary, literature references are given as tothe preparation of these compounds.

3..-.. ON Collect. Czech.

Chem. 1 Com mun. 85, NC 353 (1970).

s WTC ECHJNM cn=ctcml J..A.C.S. 71, 2949 (1949).

Chem. Ber. .96, 485

Ann. 691, 69 (1955).

J.A.C.S.50, 2828 porn Compound 9 was prepared as follows:

A mixture of 29 g (0.2 mole) of indole-3- carbonaldehyde(Org.Syn.Coll.Vol. 4, 539), 13.2 g (0.2 mole) of malodinitrile, 0.5 g ofammonium acetate and 0.5 g of acetamide in 80 ml of acetic acid wasrefluxed for 1 hour. The precipitate formed was filtered by suction andrecrystallized from ethylene glycol monomethylether/water (2:1

Yield: 26 g (67 percent). Melting point: 229230 C.

Compound was prepared as follows:

A solution of 13.3 g (0.1 mole) of Z-methylindoline 14.8 g (0.1 mole) ofethyl orthoformate and 6.6 g (0.1 mole) of malodinitrile in- 150 ml ofethylene glycol monomethyl ether was refluxed for 30 minutes. Thereaction mixture was poured into water and the precipitate was filteredoff by suction. After washing with water it was recrystallized frommethanol.

Yield: 1 l g (52 percent). Melting point: 155 C. Compound 1 l wasprepared as follows:

A suspension of 29.2 g 0.2 mole) of benzimidazole- Z-Carboxaldehyde(Chem.Ber. 98, 1330 (1965), 13.2 g (0.2 mole of malodinitrile, 0.5 g ofammonium acetate and 0.5 g of acetamide in 200 ml of acetic acid, wasrefluxed for 2 hours with stirring. The precipitate formed was filteredoff and boiled with ethylene glycol mono methyl ether. Thefiltrate waspoured into water and the precipitate after having been filtered off bysuction was washed with ether.

Yield: 6 (g percent). Melting point: above 260 C. Compound 16 wasprepared as follows:

A mixture of 39.2 g (0.2 mole) of 3-methoxy-4-B-'hydroxyethoxybenzaldehyde, prepared as described below, 13.2 g (0.2mole) of malodinitrile, 0.5 g of ammonium acetate and 0.5 g of acetamidein 80 ml of acetic acid, was refluxed for 2 hours. The precipitateformed was filtered off by suction and recrystallized from toluene.

Yield: 21.5 g (44 percent). Melting point: 148 C.

The 3-methoxy-4-B-hydroxyethoxybenzaldehyde was prepared as follows:

A mixture of 76 g (0.5 mole) of 3-methoxy-4- hydroxybenzaldehyde, 80.5 g(1 mole) of 2- chloroethanol, and 106 g 1 mole) of sodium carbonate in500 ml of diemethylformamide was refluxed for 1 hour with stirring. Themixture was concentrated by evaporation and the residue recrystallizedfrom benzene.

Yield: 67 g (69 percent). Melting point: 98 C.

While the nitrile compounds used in accordance with the presentinvention may be present in any of the water-permeable colloid layers ofthe photographic material, which are in water-permeable relationshipwith the silver halide emulsion layer e.g. a gelatin antistress layer,an intermediate layer, a filter layer, etc.

It is a particularly useful form of the invention to incorporate thenitrile compounds into the silver halide emulsion itself.

The preparation of the silver halide emulsions involves three separateoperations:

1. the emulsification and digestion or ripening of the silver halide,

2. the freeing of the emulsion from water-soluble salts usually bywashing, and

3. the second digestion or after ripening (chemical ripening) to obtainincreased sensitivity.

The compounds of use according to the present invention can be added tothe emulsion during no matter what step of emulsion preparation,preferably just before the coating of the emulsion on a suitablesupport, e.g. paper, glass, or film such as cellulose triacetate andpolyethylene terephthalate.

The compounds of use according to the invention can be used with anytype of light-sensitive material that after exposure is intended to beprocessed at elevated temperature. Various silver salts can be used aslight-sensitive salt, e.g. silver bromide, silver iodide, silverchloride or mixed silver halides, e.g. silver chlorobromide or silverbromoiodide. They are particularly yaluable to improve the fog on rapidprocessing at elevated temperature of medium or high-speed image formingsilver halide emulsions, in which the silver halide is predominantlysilver bromide, e.g. silver bromoiodide emulsions, the iodide content ofwhich is generally less than mole percent.

The silver halides are dispersed in the common hydrophilic colloids suchas gelatin, casein, zein, polyvinylalcohol, carboxymethyl cellulose,alginic acid etc. gelatin being, however, favoured.

The silver halide emulsions for being processed after exposure atelevated temperature generally are silver halide emulsions having a lowcontent of hydrophilic colloid e.g. gelatin. The ratio of hydrophiliccolloid, more particularly gelatin, to silver halide expressed as silvernitrate is generally comprised between 0.2 and 0.6.

The compounds of use according to the invention may be used in amountsvarying between very wide limits. The optimum amount for each individualcompound can be easily determined by some simple test known to thoseskilled in the art. In the silver halide emulsion they are generallyemployed in amounts comprised between 1 mg and 1,000 mg per mole ofsilver halide.

The silver halide emulsions can be sensitized chemically as well asspectrally.

They can be sensitized chemically by any of the accepted procedures. Theemulsions can be digested with naturally active gelatin or sulphurcompounds, e.g. allyl thiocyanate, allyl thiourea, sodium thiosulphateetc. The emulsions can be sensitized also by means of reductors, e.g.tin compounds as described in UK. Pat. Specification 789,823 and bymeans of small amounts of noble metal compounds, e.g. of gold, platinum,palladium, iridium, ruthenium, and rhodium as described by R. Koslowsky,Z. Wiss. Phot. 46, 67-72 (.1951). Representative noble metal compoundsare ammonium chloropalladate, potassium chloroplatinate, potassiumchloroaurate, and potassium aurithiocyanate. Of course, the emulsionscan also be sensitized chemically with a combination of the abovechemical sensitizers.

The emulsions may further comprise compounds that sensitize the emulsionby development acceleration, e.g. alkylene oxide polymers. Thesealkylene oxide polymers may be of various type, e.g. polyethylene glycolhaving a molecular weight of 1,500 or more, alkylene-oxide condensationproducts or polymers as described in US. Pat. Nos. 1,970,578 2,240,4722,423,549 2,441,389 2,531,832 and 2,533,990 and in U.1(. Pat.Specifications 920,637 940,051 945,340 991,608 and 1,015,023. Thesedevelopment accelerating compounds may also be present in the silverhalide developing solution. Other development accelerating compounds areonium and polyonium compounds preferably of the ammonium, phosphonium,and sulphonium type The emulsions can be sensitized spectrally, e.g. bymeans of the common methine dyes such as neutrocyanines, basic or acidcarbocyanines, rhodacyanines, 60 mpound.

hemicyanines, styryl dyes, oxonol dyes and the like. Such spectrallysensitizing dyes have been described by F. M. l-lamer in The cyaninedyes and related compounds (1954). w 7 M The common emulsion stabilizersor antifoggants can be added to the silver halide emulsions or thedeveloping bath. Known antifoggants or stabilizers are, e. g. sulphinicand selenic acid or salts thereof, aliphatic, aromatic or heterocyclicmercapto compounds or disulphides, e.g. benzothiazoline-2-thione andl-phenyl-S- mercaptotetrazole which may comprise sulpho groups orcarboxyl groups, nitroindazole, nitrobenztriazole, nitrobenzimidazole,mercury compounds, e.g. those described in Belgian Pat. Nos. 524,121677,337 707,386 and 709,195 and as already noted above azaindenes,particularly the tetraor pentaazaindenes and especially thosesubstituted by hydroxyor amino groups as described by Birr in Z. Wiss.Phot. 47, 2-58 (1952).

Other addenda, e.g. hardening agents such as formaldehyde, mucochloricand mucobromic acid, dialdehydes, etc. wetting agents, e.g. thefluorinated surfactants of U.K. Pat. Application No. 58431/68,plasticizers, matting agents e.g. polymethyl methacrylate and silicaparticles, colour couplers, mask-forming compounds, light-screening dyesetc. may be present in the silver halide emulsion or another layer ofthe lightsensitive materials of the invention.

The following examples illustrate the present invention:

Example 1- A silver bromoiodide X-ray emulsion ready for coatingcomprises per kg an amount of silver halide corresponding to 190 g ofsilver nitrate, 74 g of gelatin, 545 mg of 5methyl-7-hydroxy-s-triazolo[ l ,5-a]pyrimidine, 6.5 mg of1-phenyl-Smercaptotetrazole, and 0.45 mg of mercury cyanide.

The above emulsion was divided into several aliquot portions and to eachof these portions one of the nitrile compounds listed in the table belowwas added in the amount given.

The emulsion portions were coated on a polyethylene terephthalatesupport and dried.

After exposure through a continuous wedge with constant 0.15 theemulsions were processed in an automatic seconds processing machine.Development occurred for 23 seconds at 35 C in Agfa-Gevaerts hardeningdeveloper for automatic machine processing G 138 which compriseshydroquinone and l-phenyl-3- pyrazolidinone as developing agents andglutaraldehyde as hardener.

The sensitometric results obtained with the fresh materials and withmaterials that were stored before exposure and processing for 5 days at45 C and 70 percent relative humidity are listed in the table below. Thevalues given for the speed are relative values measured at density 1above fog; a value of has been given to thespeed of the fresh materialcomprising no suitable Table mg nitrile compound Fresh material Storedmaterial 100 mg of compound 3 reducing effect when processing atelevated temperature. Some compounds have a favourable effect on thegradation (compound 14) and speed (compounds 3, 6 and 14) after storage.Example 2 Example l was repeated with the difference that now thenitrile compound listed in the table below was used.

The following sensitometric results were obtained.

The above results show the favourable effect of compound 1 l on the fog,gradation as well as the speed of. the material, which was processed atelevated temperature after having been stored for days at 45 C and 70percent relative humidity.

We claim:

1. Method of producing photographic images, whichcomprises developing anexposed photographic element comprising a support and at least onephotographic silver halide emulsion, at a temperature above C, whereinthe said development is carried out in the presence of at least onenitrile compound selected from the group consisting of:

(a) benzene compounds carrying at least 2 cyano groups on the benzenenucleus (b) w-deficient heterocycles carrying at least 1 cyano group onthe heterocyclic nucleus, and

. (c) compounds carrying at least one cyano group on an olefinic group,which correspond to the for mula:

jlable f Continued mg nitrile compound Fresh material Stored materialper kg emulsion Fog Speed Fog Speed amma amma "16 mg of cefi' ifind 60.20 1.54 102 0.23 1.38 12h 10 mg of compound 9 0.18 1.32 89 0.22 1.1681 10 mg of compound 10 0.17 1.33 83 0.20 1.21 87 mg of compound 10 0.191.61 89 0.23 1.33 86 10 mg of compound 13 0.19 1.42 86 0.22 1.19 102 100mg of compound 13 0.19 1.46 86 0.21 1.27 10 mg of compound 14 0.18 1.4891 0.21 1.29 98 100 mg of compound 14 0.19 1.65 87 0.27 1.91

The above results show that the compounds used acwherein: cording to theinvention have a favourable fog- 5 R is a cyano group or a 1r-deficientheterocycle, and

R is an aryl group or a heterocycle.

2. Method according to claim 1, wherein the said nitrile compound ispresent in a silver halide emulsion.

3. Method according to claim 2, wherein the said ni- 20 trile compoundis present in an amount comprised between 1 mg and 1000 mg per mole ofsilver halide.

4. Method according to claim I, wherein the emulsion comprises anazaindene emulsion stabilizer.

5. Method according to claim 4, wherein said azain- 25 dene emulsionstabilizer is S-methyl-7-hydroxy-striazolo[ l ,5-a]pyrimidine.

6. A light-sensitive photographic silver halide material, whichcomprises besides an azaindene emulsion stabilizer at least one nitrilecompound selected from 30 the group consisting of:

a. benzene compounds carrying at least two cyano groups,

b. Ir-deficient heterocycles carrying at least one cyano group on theheterocyclic nucleus, and

0. compounds carrying at least one cyano group on an olefinic group,which correspond to the formula:

wherein:

R is a cyano group or a 'rr-deficient heterocycle, and

R is an aryl group or a heterocycle.

7. A light-sensitive photographic silver halide material according toclaim 6, wherein said nitrile compound is present in a gelatino silverhalide emulsion in ian amount comprised between 1 mg and 1,000 mg per:mole of silver halide.

8. A light-sensitive photographic material according to claim 7, whereinthe ratio of gelatin to silver halide expressed as silver nitrate in theemulsion is comprised between 0.2 and 0.6. I 9. A light-sensitivematerial according to claim 6, .wherein the azaindene emulsionstabilizer is 5-methyl-' '-7-hydroxy-s-trizolo[ l ,S-a] pyrimidine.

1. METHOD OF PRODUCING PHOTOGRAPHIC IMAGES, WHICH COMPRISES DEVELOPING AN EXPOSED PHOTOGRAPHIC ELEMENT COMPRISESING A SUPPORT AND AT LEAST ONE PHOTOGRAPHIC SILVER HALIDE EMULSION, AT A TEMPERATURE ABOVE 30*C, WHEREIN THE SAID DEVELOPMENT IS CARRIED OUT IN THE PRESENCE OF AT LEAST ONE NITRILE COMPOUND SELECTED FROM THE GROUP CONSISTING OF: (A) BENZENE COMPOUNDS CARRYING AT LEAST 2 CYANO GROUPS ON THE BENZENE NUCLEUS (B) $-DEFICIENT HETEROCYCLES CARRYING AT LAST 1 CYANO GROUP ON THE HETEROCYCLIC NUCLEUS, AND (C) COMPOUNDS CARRYING AT LEAST ONE CYANO GROUP ON AN OLEFINIC GROUP WHICH CORRESPOND TO THE FORMULA:
 2. Method according to claim 1, wherein the said nitrile compound is present in a silver halide emulsion.
 3. Method according to claim 2, wherein the said nitrile compound is present in an amount comprised between 1 mg and 1000 mg per mole of silver halide.
 4. Method according to claim 1, wherein the emulsion comprises an azaindene emulsion stabilizer.
 5. Method according to claim 4, wherein said azaindene emulsion stabilizer is 5-methyl-7-hydroxy-s-triazolo(1,5-a)pyrimidine.
 6. A light-sensitive photographic silver halide material, which comprises besides an azaindene emulsion stabilizer at least one nitrile compound selected from the group consisting of: a. benzene compounds carrying at least two cyano groups, b. pi -deficient heterocycles carrying at least one cyano group on the heterocyclic nucleus, and c. compounds carrying at least one cyano group on an olefinic group, which correspond to the formula:
 7. A light-sensitive photographic silver halide material according to claim 6, wherein said nitrile compound is present in a gelatino silver halide emulsion in an amount comprised between 1 mg and 1,000 mg per mole of silver halide.
 8. A light-sensitive photographic material according to claim 7, wherein the ratio of gelatin to silver halide expressed as silver nitrate in the emulsion is comprised between 0.2 and 0.6.
 9. A light-sensitive material according to claim 6, wherein the azaindene emulsion stabilizer is 5-methyl-7-hydroxy-s-trizolo( 1, 5-a)pyrimidine. 